| abstract |
Disclosed are an AFI-CHA mixed crystal molecular sieve and an NH 3-SCR catalyst using the same as a carrier, and the preparation methods therefor. The AFI-CHA mixed crystal molecular sieve is composed of an AFI-type SAPO-5 molecular sieve and a CHA-type SAPO-34 molecular sieve, and the crystal grains are mixed crystal grains of AFI and CHA. The mixed crystal molecular sieve is synthesized by a hydrothermal synthesis method, and can be obtained by changing the structure-directing agent, the heating rate and the roasting temperature in a preparation process. Copper is loaded on the basis of the mixed crystal molecular sieve to prepare copper-based NH3-SCR catalyst and corresponding monolithic catalyst; and the mixed crystal molecular sieve significantly improves the catalytic activity and hydrothermal stability of the catalyst. |